| 摘要 |
PURPOSE: To ensure a resting place for wild birds or a spawn place for fish and provide substitute for a green tract of slope surface without damaging a natural scene in dam having a variable level or in lakes and marshes having limited areas. CONSTITUTION: Floats 2 are mounted on a frame 1 having any external form. While the frame 1 is held under the surface of the water, a planting substratum material 4 consisting of vegetable fibers or synthetic fiber lumps is laminated on the frame 1 and float 2 to be held on the surface of the water. The lower and upper surfaces of the substratum material 4 are covered with nets 3a, 3b to be locked so that the substratum material is fastened to the frame 1 by fastening material such as a rope, wire and bolt. |
